In this work, I used Krita’s standard brushes: Basic 3-flow, basic 4-opacity, airbrush, free and polygonal selections. It was a lot of fun and a great learning experience!
Mouths on the side of the face are so creepy.
But if you care about it, I think you can easily fix it in this case.
Just move the mouth to the edge of the face and add a bump to indicate the top lip.
You can get away without the bottom lip since the hand is covering it.